One part in a radio transceiver is a radio frequency (RF) low noise amplifier (LNA), which may be used in either a receiver or a transmitter of the radio transceiver. The performance requirements for the RF LNA comprise low noise contribution, high gain amplification, and good linearity. For example, the RF LNA in a receiver will boost an electrical signal above a noise threshold of subsequent stages in the receiver while contributing very little noise to the electrical signal.
Impedance matching between the RF LNA and filters and/or other devices is needed in order to provide proper frequency response for the filters and/or other devices connected to the RF LNA. Conventional devices, systems, and methods may be insufficient to provide adjustable gain control while maintaining a substantially constant input impedance. As such, devices, systems, and methods for providing adjustable gain control while maintaining the input impedance are needed.